frica’s East A Great Rift Valley: A Complex Rift System
Journal Article Review

Stephen Underwood, Instructor
PHSC 210
Elements of Earth Science
March 23, 2012

Introduction The East African Rift System (EARS) seems to be one of the most amazing geographic studies of the world. A rift can be defined as a split in the earth’s surface that becomes wider over time. In this case, the EARS has developed into two plates or branches, which have been named the Nubian Plate and the Somalian Plate. The two branches include a west branch, which consists of the African Great Lakes, and a nearly parallel east branch, which divides Kenya from north to south and enters Tanzania. Because the two branches have become so distinct, there is a common misconception that there is only a single rift in East Africa. However, geologists have discovered a series of rifts in Africa. Thus, the growing number of rifts has become of interest to many geologists and scientist.

Brief Overview and Main Points
In this article, James Wood and Alex Guth discuss the geographic and physical structure of the East African Rift System as well as the underlying causes of rift formation. The East African Rift (EAR) involves a fracture that has resulted in two branches-- a western branch, consisting of the East African Great Lakes, and an Eastern branch, dividing Kenya completely and entering Tanzania. The EAR has been grouped with other rifts, especially the Ethiopian rift, to form the East African Rift System (Wood & Guth, 2005).
Although the exact cause of rifts is still under debate, some models have been formed to explain the formation of rifts. One of the most popular explanations suggests that mantle plumes under the continent caused extreme heating of the crust and created thermal bulges. The thermal bulges continue to expand and fracture the crust, leading to the split of the surface. On the other hand, other scientists attribute the African rifts to the hot spot located under central Kenya. They suggest that the Kenya Dome (hot spot) caused the initial Ethiopian rift. However, despite what the cause of these rifts may be, they have become prevalent throughout Africa.

Article Strengths
In this article, Wood and Guth create a detailed description of the physical and geographic characteristics of the East African Rift System. They explain where the rifts are located, how the area is separating into multiple plates, and how the series of rifts, including the East African Rift and the Ethiopian Rift, make up the East African Rift System. As a whole, the authors’ explanations are clear. In addition, the authors present explanations concerning the formation of rifts. By explaining the various conclusions and models that scientists have developed for rift formation, they enable readers to understand some of the possible causes of these separations in the earth’s surface.

Article Weakness
The article details what the East African Rift System is and presents some of the possible causes of the rifts. However, the authors could have gone into greater depth regarding the actual formation of rifts. Although they explain that most geologists attribute the rift formation to thermal bulges and that some scientists relate the African rift formation to hot spots underneath the continent, they limit their explanation of the reasoning behind these conclusions. By elaborating on what indications allowed scientists to form these discoveries and conclusions, the authors would have given the readers a better understanding of the actual rifting process and the causes of rift formation.

Conclusion
In conclusion, the East African Rift System is a series of fractures in the earth’s surface that is continuing to widen as time progresses. Since the rifts have been discovered, geologists and scientists have studied the geographic and natural attributes of them. Although scientists have proposed possible causes of the rifts, they have not been able to determine the exact process of rift formation. This article presents detailed descriptions of the rifts as well as potential explanations of rift formation. However, after reading this article, it is obvious that further research can be done to clarify the rift’s causes and their formation process.

Bibliography

Wood, J., & Guth, A. (2005), East Africa’s Great Rift Valley: A Complex Rift System.